Method of verifying fault of inspection unit, inspection apparatus and inspection system

ABSTRACT

A method of verifying a fault of an inspection unit, an inspection apparatus, and an inspection system are disclosed. The method according to the present disclosure includes: providing a verification reference body which is formed on a frame attached to an inspection system; placing the inspection unit on the verification reference body; obtaining image data of the verification reference body through the inspection unit; verifying a fault of the inspection unit by extracting a movement error and height error of the inspection unit from the image data; and generating a verification result indicating the fault of the inspection unit.

TECHNICAL FIELD

The present disclosure relates to a method of verifying a fault of aninspection unit, an inspection apparatus and an inspection system.

BACKGROUND ART

In general, at least one Printed Circuit Board (PCB) is provided in anelectronic device and various circuit elements such as circuit patterns,connection pads, and driving chips electrically connected with theconnection pads are mounted on the PCB.

A substrate formed by mounting electronic elements on a PCB is used invarious electronic products. The substrate is manufactured by applyinglead to pad areas of a bare substrate and coupling terminals of theelectronic elements to the lead-applied areas.

A substrate inspection system performs a solder paste inspection (SPI)that inspects whether lead is properly applied to the pad areas of thePCB before the electronic elements are mounted on the PCB, and anautomated optical inspection (AOI) that detects various types of defectsrelating to whether the electronic elements are properly soldered to thePCB after the electronic elements are mounted on the PCB.

In the related art, a user has checked an inspection result of aninspection object, and when the inspection result was bad, the user hasstopped the substrate inspection system, mounted a calibration target ona work stage, and performed a calibration of the substrate inspectionsystem. Accordingly, it is impossible to know whether the inspectionperformance has deteriorated, until a user checks the inspection result,so that there is the problem that PCBs that have not been properlyinspected are manufactured as products.

SUMMARY

The present disclosure provides a method of verifying whether aninspection unit, capable of inspecting a defect of an inspected body, inan inspection apparatus has a fault, and an inspection system.

According to one embodiment of the present disclosure, there is provideda method of verifying whether an inspection unit, capable of inspectinga defect of an inspected body, in an inspection system has a fault, themethod including: providing a verification reference body formed on aframe attached to the inspection system; positioning the inspection unitover the verification reference body; obtaining image data of theverification reference body through the inspection unit; verifyingwhether the inspection unit has a fault by extracting a movement errorand a height error of the inspection unit from the image data; andgenerating a verification result indicating whether the inspection unithas a fault.

In an embodiment, the verification reference body includes a flat platehaving a flat area capable of indicating a height reference and a graylevel, at least two fiducial markers disposed around the flat area, anda height marker disposed around the flat area, and verifying whether theinspection unit has a fault includes: extracting a movement error of theinspection unit from image data of the at least two fiducial makers; andextracting a height error of the inspection unit from image data of theflat plate or the height marker.

In an embodiment, the verification reference body includes at least twofiducial markers, a flat plate indicating a height reference and havinga flat area defined by the at least two fiducial markers, and a heightmarker disposed around the flat area, and verifying whether theinspection unit has a fault includes: extracting a movement error of theinspection unit from image data of the at least two fiducial markers;and extracting a height error of the inspection unit from image data ofthe flat plate or the height marker.

In an embodiment, the flat plate indicates a height reference forverifying an accuracy of the height of the inspection unit.

In an embodiment, the at least two fiducial markers indicate at leasttwo positions for verifying an accuracy of movement of the inspectionunit.

In an embodiment, the height marker indicates a predetermined height forverifying an accuracy of height measurement of the inspection unit.

In an embodiment, extracting a movement error of the inspection unitincludes: detecting the position of the at least two fiducial markersfrom the image data of the at least two fiducial markers; and verifyingwhether the inspection unit has a fault by comparing the detectedposition with a predetermined reference position of the at least twofiducial markers.

In an embodiment, extracting a height error of the inspection unitincludes: detecting the height of the height marker using the image dataof the flat plate or the height marker; and verifying whether theinspection unit has a fault by comparing the detected height with apredetermined height of the height marker.

In an embodiment, positioning the inspection unit over the verificationreference body includes positioning the inspection unit over theverification reference body based on an inspection defect rate of theinspection unit.

In an embodiment, the method further includes correcting a fault of theinspection unit by calibrating the inspection unit based on theverification result.

According to another embodiment of the present disclosure, there isprovided an inspection apparatus for verifying whether an inspectionunit, capable of inspecting a defect of an inspected body, in aninspection system has a fault, the inspection apparatus including: aframe attachable to the inspection system; and a verification referencebody formed on the frame, and the verification reference body includes aflat plate having a flat area capable of indicating a height referenceand a gray level, at least two fiducial markers disposed around the flatarea, and a height marker disposed around the flat area.

According to yet another embodiment of the present disclosure, there isprovided an inspection apparatus for verifying whether an inspectionunit, capable of inspecting a defect of an inspected body, in aninspection system has a fault, the inspection apparatus including: aframe attachable to the inspection system; and a verification referencebody formed on the frame, and the verification reference body includesat least two fiducial markers, a flat plate indicating a heightreference and having a flat area defined by the at least two fiducialmarkers, and a height marker disposed around the flat area.

In an embodiment, the flat plate indicates a height reference forverifying an accuracy of the height of the inspection unit.

In an embodiment, the at least two fiducial markers indicate at leasttwo positions for verifying an accuracy of movement of the inspectionunit.

In an embodiment, the height marker indicates a predetermined height forverifying an accuracy of height measurement of the inspection unit.

In an embodiment, the verification reference body is disposed in aconcave portion of the frame.

In an embodiment, the inspection apparatus further includes: a coverconfigured to be capable of opening and closing the verificationreference body disposed in the concave portion; and a driving unitmoving the cover with respect to the verification reference body to openand close the verification reference body.

In an embodiment, the driving unit includes a rotating unit configuredto rotate the cover to open and close the verification reference body.

In an embodiment, the driving unit includes a sliding unit configured toslide the cover to open and close the verification reference body.

In an embodiment, the inspection apparatus further includes a reflectordisposed on the frame to verify whether a light source, configured togenerate light, in the inspection unit has a fault.

In an embodiment, the reflector has a convex curve shape.

In an embodiment, the reflector has a concave curve shape.

According to yet another embodiment of the present disclosure, there isprovided an inspection system including: an inspection unit capable ofinspecting a defect of an inspected body; the inspection apparatusaccording to another embodiment; and a controller configured to positionthe inspection unit over the verification reference body, obtain imagedata of the verification reference body through the inspection unit,verify whether the inspection unit has a fault, and generate averification result indicating whether the inspection unit has a fault.

In an embodiment, the controller is configured to position theinspection unit over the verification reference body based on aninspection defect rate of the inspected body by the inspection unit.

In an embodiment, the controller is configured to correct a fault of theinspection unit by calibrating the inspection unit based on theverification result.

According to the present disclosure, it is possible to automaticallycheck whether the inspection performance of an inspection system hasdeteriorated without depending only on the user's empirical knowledge,so it is possible to improve a yield rate by reducing inspected bodiesfrom being manufactured into products without properly undergoinginspection.

Further, according to the present disclosure, it is possible toautomatically verify whether an inspection unit has a fault and performa calibration of the inspection unit, depending on a fault of theinspection unit, so it is possible to efficiently manage the operationtime of the inspection system.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram schematically showing a configuration of aninspection system according to an embodiment of the present disclosure.

FIG. 2 is a diagram schematically showing a configuration of aninspection unit according to an embodiment of the present disclosure.

FIG. 3 is a perspective view schematically showing a configuration of aninspection apparatus according to an embodiment of the presentdisclosure.

FIG. 4A is a side view showing an example of a reflector according to anembodiment of the present disclosure.

FIG. 4B is a side view showing another example of the reflectoraccording to an embodiment of the present disclosure.

FIG. 5A is an exemplary view showing a state in which a verificationreference body is open by moving a cover according to an embodiment ofthe present disclosure.

FIG. 5B is an exemplary view showing a state in which the coveraccording to an embodiment of the present disclosure is positioned overthe verification reference body.

FIG. 6 is a flowchart showing a process of verifying whether theinspection unit has a fault and performing calibration of the inspectionunit through a second verification target according to an embodiment ofthe present disclosure.

FIG. 7 is a flowchart showing a process of verifying whether aninspection unit has a fault through the reflector according to anembodiment of the present disclosure.

FIG. 8A is an exemplary view showing normality of a lighting portionaccording to an embodiment of the present disclosure.

FIG. 8B is an exemplary view showing abnormality of a lighting portionaccording to an embodiment of the present disclosure.

FIG. 9 is a flowchart showing a process of providing a verificationresult according to an embodiment of the present disclosure.

FIG. 10 is an exemplary view showing a list of verification resultsaccording to an embodiment of the present disclosure.

FIG. 11 is an exemplary view showing a chart of the verification resultsaccording to an embodiment of the present disclosure.

DETAILED DESCRIPTION

Hereinafter, exemplary embodiments of the present disclosure will bedescribed with reference to the accompanying drawings. However, in thefollowing description, a detailed description of widely known functionsor elements will be omitted, in case there is concern of unnecessarilymaking the gist of the present disclosure unclear.

FIG. 1 is a perspective view schematically showing an inspection systemaccording to an embodiment of the present disclosure. Referring to FIG.1, an inspection system 100 includes an inspection unit 110. Theinspection unit 110 obtains image data of an inspected body by radiatinglight towards the inspected body and receiving light reflected from theinspected body, and inspects the inspected body based on the image data.In an embodiment, the inspected body includes a printed circuit boardand the light includes pattern light and color light, but they are notlimited thereto.

FIG. 2 is a diagram schematically showing a configuration of theinspection unit 110 according to an embodiment of the presentdisclosure. Referring to FIG. 2, the inspection unit 110 includes firstlighting portions 210-1 and 210-2. The first lighting portions 210-1 and210-2 radiate pattern light towards an inspected body B to measure aninspection object IO formed on the inspected body B. The inspectionobject IO includes a solder (not shown) formed on a pad of the inspectedbody B, electronic elements (not shown) or the like, however it is notlimited thereto and may include all materials having a shape such asglass, plastic, and metals.

In an embodiment, the first lighting portions 210-1 and 210-2 include alight source 211 configured to generate light, a grating element 212configured to convert the light from the light source 211 into patternlight, a grating-moving apparatus 213 configured to pitch-move thegrating element 212, and a projection lens 214 configured to project thepattern light, which is converted by the grating element 212, onto theinspection object IO. The grating element 212 may be moved by apredetermined distance (e.g., 2π/N (where N is a natural number of 2 ormore) through the grating-moving apparatus 213, such as a PZT (piezo)actuator, for phase transition of the pattern light. Alternatively,instead of using the grating element 212 and the grating-movingapparatus 213, it is possible to radiate the pattern light, using animage of a liquid crystal display (not shown). However, the presentdisclosure is not limited thereto and any other means may be used aslong as it can radiate pattern light.

In an embodiment, one first lighting portion 210-1 or 210-2 may beinstalled or a plurality of first lighting portions may be installed tobe spaced apart by a predetermined angle along a circumferentialdirection or a virtual polygonal plane. In another embodiment, aplurality of first lighting portions 210-1 and 2102 may be installed tobe spaced apart by a predetermined interval along a direction that isperpendicular to the inspected body B. In yet another embodiment, onefirst lighting portion 210-1 or 210-2 may be installed along a directionthat is perpendicular to the inspected body B.

The inspection unit 110 further includes a second lighting portion 220.The second lighting portion 220 radiates color light toward theinspected body B to measure the inspection object IO formed on theinspected body B. For example, the color light includes white light, redlight, green light and blue light, however the color light is notlimited thereto. In an embodiment, the second lighting portion 220includes a first lamp 221, a second lamp 222, and a third lamp 223.

The first lamp 221 is installed under the first lighting portions 210-1and 210-2. The first lamp 221 generates the color light, and radiatesthe color light towards the inspected body B. In an embodiment, thefirst lamp 221 may have a shape of a circle or a virtual polygon,however the first lamp 221 is not limited thereto. The first lamp 221includes a first ring member 221 a having an opening TH₁ for passinglight (e.g., pattern light or color light) and at least one first lightemitting element 221 b, which is installed under the first ring member221 a, as a light source for generating the color light.

In an embodiment, the first lamp 221 may generate at least one colorlight. As one example, the first lamp 221 may generate color lighthaving a first color (e.g., red). As another example, the first lamp 221may generate color lights of red, green, and blue. The second lamp 222is installed under the first lamp 221. The second lamp 222 generatescolor light and radiates the color light towards the inspected body B.In an embodiment, the second lamp 222 may have a shape of a circle or avirtual polygon, however the second lamp 222 is not limited thereto. Thesecond lamp 222 includes a second ring member 222 a having an openingTH₂ for passing light (e.g., pattern light or color light) and at leastone second light emitting element 222 b, which is installed under thesecond ring member 222 a, as a light source for generating the colorlight. In an embodiment, the opening TH₂ of the second lamp 222 may belarger in diameter than the opening TH₁ of the first lamp 221 so thatthe pattern light from the first lighting portions 210-1 and 210-2 orthe color light from the first lamp 221 can be radiated towards theinspected body B, or light (e.g., pattern light or color light)reflected from the inspected body B can be radiated.

In an embodiment, the second lamp 222 may generate at least one colorlight. As one example, the second lamp 222 may generate a color lighthaving a color (e.g., green) that is different from that of the colorlight generated by the first lamp 221. As another embodiment, the secondlamp 222 may generate color lights of red, green, and blue.

The third lamp 223 is installed under the second lamp 222. The thirdlamp 223 generates color light, and radiates the color light towards theinspected body B. In an embodiment, the third lamp 223 may have a shapeof a circle or a virtual polygon, however the third lamp 223 is notlimited thereto. The third lamp 223 includes a third ring member 223 ahaving an opening TH₃ for passing light (e.g., pattern light or colorlight) and at least one third light emitting element 223 b, which isinstalled under the third ring member 223 a, as a light source forgenerating the color light. In an embodiment, the opening TH₃ of thethird lamp 223 may be larger in diameter than the opening TH₂ of thesecond lamp 222 so that the pattern light from the first lightingportions 210-1 and 210-2 or the color light from the first lamp 221 orsecond lamp 222 can be radiated towards the inspected body B or thelight (e.g., pattern light or color light) reflected from the inspectedbody B can be radiated.

In an embodiment, the third lamp 223 may generate at least one colorlight. As one example, the third lamp 223 may generate a color lighthaving a color (e.g., green) that is different from that of the colorlight generated by the first lamp 221 and the second lamp 222. Asanother embodiment, the third lamp 223 may generate color lights of red,green, and blue.

Although the second lighting portion 220 includes the first lamp 221,the second lamp 222, and the third lamp 223 in the embodiment describedabove, however the second lighting portion 220 is not limited thereto.For example, the second lighting portion 220 may include at least onelamp.

The inspection unit 110 further includes an imaging portion 230. Theimaging portion 230 obtains image data of the inspected body B byreceiving light reflected by the inspected body B. That is, the imagingportion 230 obtains the image data of the inspected body B byphotographing the inspected body B through the radiation of the patternlight from the first lighting portions 210-1 and 210-2. Further, theimaging portion 230 obtains the image data of the inspected body B byphotographing the inspected body B through the radiation of the colorlight from the second lighting portion 220. As one example, the imagingportion 230 may be installed at an upper position perpendicular to theinspected body B. As another example, a plurality of imaging portions230 may be installed at an upper position perpendicular to the inspectedbody B and may be installed along a circumferential direction to bespaced apart by a predetermined angle. The imaging portion 230 may be acharge coupled device (CCD) camera or a complementary metal oxidesemiconductor (CMOS) camera, however the imaging portion 230 is notlimited thereto.

The inspection unit 110 shown in FIG. 2 is an example of an inspectiondevice that can obtain image data of the inspected body B, so it shouldbe noted that the inspection unit 110 is not limited to theconfiguration shown in FIG. 2.

Referring back to FIG. 1, the inspection system 100 further includes amoving unit 120. The moving unit 120 moves the inspected body B to theinspection unit 110. The moving unit 120 may include a conveyer (notshown) or the like, but the moving unit 120 is not limited thereto.

The inspection system 100 further includes an inspection apparatus 130for verifying whether the inspection unit 110 has a fault. In anembodiment, the inspection apparatus 130 may be attached to a side ofthe inspection system 100. For example, the inspection apparatus 130 isattached to a side of the moving unit 120, however the inspectionapparatus 130 is not limited thereto.

FIG. 3 is a perspective view schematically showing a configuration ofthe inspection apparatus 130 according to an embodiment of the presentdisclosure. Referring to FIG. 3, the inspecting apparatus 130 includes aframe 310 that can be attached to the inspection system 100, and averification reference body 320 formed on the frame 310. In anembodiment, the verification reference body 320 may be disposed in aconcave portion of the frame 310 as shown in FIG. 3, however theverification reference body 320 is not limited thereto. For example, theverification reference body 320 may be disposed on the frame 310.

The verification reference body 320 may include a first verificationtarget 321, a second verification target 322, and a third verificationtarget 323.

The first verification target 321 is a verification target thatindicates a height reference for verifying light radiated from theinspection unit 110 and a reference plane for measuring height of theinspection unit 110. For example, the first verification target 321includes a flat plate 321 b having a flat area 321 a that can indicatethe height reference. Also, the flat area 321 a can indicate one or moregray level (e.g., gray) or a color including one or more gray level.

The second verification target 322 is a verification target forverifying the accuracy of movement of the inspection unit 110. That is,the second verification target 322 is a verification target forverifying whether the inspection unit 110 moves accurately to apredetermined position. The second verification target 322 may includeat least two fiducial markers representing at least two positions forverifying the accuracy of movement of the inspection unit 110. As oneexample, the second verification target 322 includes a first fiducialmarker 322 a, a second fiducial marker 322 b, and a third fiducialmarker 322 c, as shown in FIG. 3. The first to third fiducial markers322 a to 322 c are markers for verifying the movement of the inspectionunit 110, and in detail, the first to third fiducial markers 322 a to322 c are markers for verifying X and Y offset or X, Y, and Z skew. Asanother example, the second verification target 322 may include twofiducial markers and the two fiducial markers may be disposed inparallel with the longitudinal direction of the frame 310 or may bedisposed at different positions.

The third verification target 323 is a verification target for verifyingthe accuracy of height measurement of the inspection unit 110. The thirdverification target 323 may include at least one height target having apredetermined height for verifying the accuracy of height measurement ofthe inspection unit 110. For example, the third verification target 323includes a first height target 323 a having a first height and a secondheight target 323 b having a second height, as shown in FIG. 3.

In an embodiment, the second verification target 322, that is, the atleast two fiducial markers may be disposed around the flat area 321 a.Further, the third verification target 323, that is, the at least oneheight marker may be disposed around the flat area 321 a.

In another embodiment, the flat area 321 a may be defined by the secondverification target 322, that is, the at least two fiducial markers.Further, the third verification target 323, that is, the height markermay be disposed around the flat area 321 a.

Optionally, the verification reference body 320 may further include areflector 324. The reflector 324 is a verification target for verifyingwhether the light source that generates light in the inspection unit 110has a fault. That is, the reflector 324 is a verification target forverifying whether the second lighting portion 220 that generates thecolor light in the inspection unit 110 has a fault. The reflector 324may have various shapes to reflect the color light radiated from theinspection unit 110. As one example, the reflector 324 may have a convexcurve shape, as shown in FIG. 4A. As another example, the reflector 324may have a concave curve shape, as shown in FIG. 4B.

The inspection apparatus 130 further includes a cover 330. The cover 330opens the verification reference body 320 while a fault of theinspection unit 110 is verified, and covers the verification referencebody 320 to prevent dirt, dust or the like from entering theverification reference body 320 while a defect of the inspection unit110 is not verified.

The inspection apparatus 130 further includes a driving unit 340. Thedriving unit 340 moves the cover 330 with respect to the verificationreference body 320 to open and close the verification reference body320. That is, when the verification of a fault of the inspection unit110 is started, the driving unit 340 moves the cover, which is over theverification reference body 320, to a predetermined position to open theverification reference body 320. For example, the driving unit 340 movesthe cover 330, which is over the verification reference body 320, to apredetermined position (180 degrees rotated position), as shown in FIG.5A. Further, when the verification of a fault of the inspection unit 110is completed, the driving unit 340 moves the cover 330, which is at thepredetermined position, over the verification reference body 320 tocover the verification reference body 320, as shown in FIG. 5B. In anembodiment, the driving unit 340 includes a rotating unit that rotatesthe cover 330 by a predetermined angle (e.g., 180 degrees) to open andclose the verification reference body 320. In another embodiment, thedriving unit 340 includes a sliding unit that slides the cover 330 toopen and close the verification reference body 320.

The inspection apparatus 130 further includes a stopper 350. The stopper350 supports the cover 330 to maintain the cover 330, which is moved bythe driving unit 340, over the verification reference body 320.

Referring back to FIG. 1, the inspection system 100 further includes acontroller 140. In addition, the inspection system 100 may furtherinclude a storage unit (not shown), a user input unit (not shown), andan output unit (not shown). In an embodiment, the user input unit mayinclude a keyboard, mouse or the like, and the output unit may include adisplay unit, a speaker or the like, however they are not limitedthereto.

The controller 140 positions the inspection unit 110 over the inspectionapparatus 130, obtains image data of the verification reference body 320through the inspection unit 110, verifies whether the inspection unit110 has a fault, and generates a verification result indicating whetherthe inspection unit 110 has a fault. Further, the controller 140corrects the fault of the inspection unit 110 by calibrating theinspection unit 110 based on the generated verification result. Inaddition, the controller 140 controls the movement of each component ofthe inspection system 100, for example, the inspection unit 110, themoving unit 120, and the driving unit 340. In an embodiment, thecontroller 140 automatically performs the verification whether theinspection unit 110 has a fault in accordance with predeterminedinformation. As one example, the predetermined information may includean inspection defect rate of the inspected body B. In this case, thecontroller 140 checks the inspection defect rate of the inspected bodyB, and automatically performs the verification whether the inspectionunit 110 has a fault when the inspection defect rate of the inspectedbody B exceeds a predetermined threshold value. As another example, thepredetermined information may include cycle information. The cycleinformation is information indicating the cycle of automaticallyverifying whether the inspection unit 110 has a fault. For example, thecycle information includes a cycle of every week, every second week,every month, every second month, or the like.

Although the controller 140 positions the inspection unit 110 over theinspection apparatus 130 in accordance with predetermined information inthe embodiment described above, the present disclosure is not limitedthereto, and the controller 140 may position the inspection unit 110over the inspection apparatus 130 in accordance with user inputinformation requesting the fault verification of the inspection unit110. In this case, the controller 140 may determine whether theinspected body B is present on the moving unit 120 of the inspectionsystem 100, and may position the inspection unit 110 over the inspectionapparatus 130 in accordance with the user input information if it isdetermined that the inspected body B is not present on the moving unit120.

In an embodiment, the controller 140 generates a control signal fordriving the driving unit 340. For example, the controller 140 generatesa first control signal for driving the driving unit 340 in accordancewith predetermined information, and outputs the first control signal tothe driving unit 340. Accordingly, the driving unit 340 moves the cover330 in response to the first control signal from the controller 140,whereby the verification reference body 320 is opened. Further, when theverification whether the inspection unit 110 has a fault is completed,the controller 140 generates a second control signal for driving thedriving unit 340, and outputs the second control signal to the drivingunit 340. Accordingly, the driving unit 340 moves the cover 330 over theverification reference body 320 in response to the second control signalfrom the controller 140. Thereby the verification reference body 320 isclosed to prevent dirt, dust or the like from entering the verificationreference body 320.

In an embodiment, the controller 140 obtains the image data of theverification reference body 320 through the inspection unit 110 movedover the inspection apparatus 130, and verifies whether the inspectionunit 110 has a fault based on the obtained image data.

As one example, the controller 140 positions the inspection unit 110over the first verification target 321, generates a control signal fordriving the inspection unit 110 and outputs the control signal to theinspection unit 110. Accordingly, the inspection unit 110 obtains theimage data of the first verification target 321 by radiating light(color light or pattern light) towards the first verification target 321and receiving light reflected from the first verification target 321, inresponse to the control signal from the controller 140. The controller140 verifies whether the inspection unit 110 has a fault based on theimage data of the first verification target 321 obtained through theinspection unit 110. That is, the controller 140 verifies the accuracyof the amount of light, the setting of the reference plane, and themovement amount of the pattern of the inspection unit 110 based on theimage data of the first verification target 321.

As another example, the controller 140 positions the inspection unit 110over the second verification target 322, generates a control signal fordriving the inspection unit 110 and outputs the control signal to theinspection unit 110. Accordingly, the inspection unit 110 obtains imagedata of the second verification target 322 by radiating light (colorlight or pattern light) towards the second verification target 322 andreceiving light reflected from the second verification target 322, inresponse to the control signal from the controller 140. That is, theinspection unit 110 obtains image data corresponding to each of the atleast two fiducial markers. The controller 140 verifies whether theinspection unit 110 has a fault based on the image data of the secondverification target 322 obtained through the inspection unit 110. Thatis, the controller 140 verifies the accuracy of movement of theinspection unit 110 based on the image data of the second verificationtarget 322.

As yet another example, the controller 140 positions the inspection unit110 over the third verification target 323, generates a control signalfor driving the inspection unit 110 and outputs the control signal tothe inspection unit 110. Accordingly, the inspection unit 110 obtainsimage data of the third verification target 323 by radiating light(color light or pattern light) towards the third verification target 323and receiving light reflected by the third verification target 323, inresponse to the control signal from the controller 140. The controller140 verifies whether the inspection unit 110 has a fault based on theimage data of the third verification target 323 obtained through theinspection unit 110. That is, the controller 140 verifies the accuracyof the height measurement of the inspection unit 110 based on the imagedata of the third verification target 323.

FIG. 6 is a flowchart showing a process of automatically verifyingwhether the inspection unit 110 has a fault and performing calibrationthrough the second verification target 322 according to an embodiment ofthe present disclosure. Referring to FIG. 6, while performing aninspection process (e.g., a PCB inspection process) of the inspectedbody B, the controller 140 stops the inspection process of the inspectedbody B when a verification cycle is reached in accordance withpredetermined information (e.g., predetermined verification cycle), andpositions the inspection unit 110 over the second verification target322 based on the predetermined reference position information of thesecond verification target 322 (S602). At this time, the verificationreference body 320 is in an open state. The controller 140 generates areference input value (S604), and outputs the generated reference inputvalue to the inspection unit 110 (S606). The reference input value maybe an input value for driving the inspection unit 110, and may be aninput value for controlling the generation of the pattern light, theradiation of the pattern light, the reception of the reflected patternlight, and the acquisition of image data of the inspection unit 110.However, the reference input value is not limited thereto. Accordingly,the inspection unit 110 obtains image data of the verification referencebody 320 by generating light, radiating the light towards theverification reference body 320 and receiving light reflected from theverification reference body 320 in accordance with the reference inputvalue from the controller 140 (S608). For example, the inspection unit110 obtains image data (hereafter, referred to as “first image data”) ofthe verification reference body 320 including the first fiducial marker322 a by radiating the light towards the verification reference body 320and receiving the light reflected from the verification reference body320, in a state in which the inspection unit 110 is positioned over thefirst fiducial marker 322 a of the second verification target 322. Next,the inspection unit 110 obtains image data (hereafter, referred to as“second image data”) of the verification reference body 320 includingthe second fiducial marker 322 b by radiating the pattern light towardsthe verification reference body 320 and receiving the pattern lightreflected from the verification reference body 320, in a state in whichthe inspection unit 110 is positioned over the second fiducial marker322 b of the second verification target 322, according to the control ofthe controller 140. Next, the inspection unit 110 obtains image data(hereafter, referred to as “third image data”) of the verificationreference body 320 including the third fiducial marker 322 c byradiating the pattern light towards the verification reference body 320and receiving the pattern light reflected from the verificationreference body 320, in a state in which the inspection unit 110 ispositioned over the third fiducial marker 322 c of the secondverification target 322, according to the control of the controller 140.

The controller 140 compares the image data (i.e., the image data of theverification reference body 320) provided from the inspection unit 110with predetermined reference data (S610), and verifies whether theinspection unit 110 has a fault (S612). For example, the controller 140compares the first image data with the predetermined reference data, andverifies whether there is an error between the position of the firstfiducial marker 322 a in the first image data and the position of thefirst fiducial marker 322 a in the predetermined reference data.Further, the controller 140 compares the second image data with thepredetermined reference data, and verifies whether there is an errorbetween the position of the second fiducial marker 322 b in the secondimage data and the position of the second fiducial marker 322 b in thepredetermined reference data. In addition, the controller 140 comparesthe third image data with the predetermined reference data, and verifieswhether there is an error between the position of the third fiducialmarker 322 c in the third image data and the position of the thirdfiducial marker 322 c in the predetermined reference data.

If it is determined that the inspection unit 110 has no fault (i.e., theinspection unit 110 is normal) in step S612, the controller 140generates a first verification result indicating that the inspectionunit 110 is normal (S614), and outputs the first verification resultthrough the output unit of the inspection system 100 (S616). In anembodiment, the first verification result may include a verificationresult value of the inspection unit 110. Further, the first verificationresult may be output in various forms (e.g., text, sound or the like).

Meanwhile, if it is determined that the inspection unit 110 has a faultin step S612, the controller 140 performs the calibration of theinspection unit 110 based on the image data of the second verificationtarget 322 and the predetermined reference data (S618). For example, thecontroller 140 performs the calibration of the inspection unit 110 tocorrect the error between the positions of the first to third fiducialmarkers 322 a to 322 c in the image data of the second verificationtarget 322 and the positions of the first to third fiducial markers 322a to 322 c in the predetermined reference data.

Further, the controller 140 may generate second verification resultindicating that the inspection unit 110 has a fault (S620), and mayoutput the second verification result through the output unit (S622). Inan embodiment, the second verification result may include a verificationresult value of the inspection unit 110. Further, the secondverification result may be output in various forms (e.g., text, sound orthe like).

The controller 140 may automatically verify whether the inspection unit110 has a fault (fault in regard to height measurement, amount of thepattern light, degree of movement of the pattern light, and referenceplane) by performing the process similar to the process shown in FIG. 6on the first verification target 321 and the third verification target323, and may perform the calibration of the inspection unit 110,depending on whether the inspection unit 110 has a fault.

Meanwhile, if it is verified that the inspection unit 110 has a fault instep S612 in accordance with the set method, the process goes to stepsS620 and S622, and the second verification result may be output throughthe output unit.

FIG. 7 is a flowchart showing a process of verifying whether theinspection unit 110 has a fault through the reflector 324 according toan embodiment of the present disclosure. Referring to FIG. 7, thecontroller 140 positions the inspection unit 110 over the reflector 324based on predetermined reference position information of the reflector324 (S702). In an embodiment, the controller 140 may position theinspection unit 110 over the reflector 324 after stopping the inspectionprocess which is running in accordance with predetermined information(e.g., the predetermined verification cycle), or before or afterverifying whether the inspection unit 110 has a fault using any one ofthe first to third verification targets 321 to 323.

The controller 140 generates a reference input value for driving theinspection unit 110 (S704), and outputs the generated reference inputvalue to the inspection unit 110 (S706). The reference input value maybe an input value for driving the inspection unit 110, and may be aninput value for controlling the generation of the color light, theradiation of the color light, the reception of the reflected colorlight, and the acquisition of the image data of the inspection unit 110.However, the reference input value is not limited thereto. Accordingly,the inspection unit 110 obtains image data of the reflector 324 byradiating the color light towards the reflector 324 and receiving thecolor light reflected from the reflector 324, in accordance with thereference input value from the controller 140. For example, when theinspection unit 110 is equipped with light emitting elements 221 b and22 b of white, red, green, blue or the like, the controller 140 mayposition the inspection unit 110 at a position where each color lightcan be radiated towards the reflector 324 through the control of the X,Y and Z axes, and then may obtain the image data radiated towards thereflector 324 by controlling the emission of each color light.

The controller 140 compares the image data (i.e., the image data of thereflector 324) provided by the inspection unit 110 with predeterminedreference data (S710), and verifies whether the inspection unit 110 hasa fault (S712). For example, the controller 140 compares the image dataof the reflector 324 with the predetermined reference data of thereflector 324, and determines whether the light emitting elements 221 band 222 b of the second lighting portion 220 of the inspection unit 110are all normal as shown in FIG. 8A, or whether some of the lightemitting elements 221 b and 222 b of the second lighting portion 220 ofthe inspection unit 110 are abnormal as shown in FIG. 8B.

If it is verified in step S712 that the inspection unit 110 has no fault(i.e., it is verified that the light sources (i.e., the first lightemitting element 221 b or the second light emitting element 222 b) ofthe second lighting portion 220 are normal), the controller 140generates a first verification result indicating that the inspectionunit 110 is normal (S714), and outputs the generated first verificationresult through the output unit (S716). The first verification result maybe output in various forms (e.g., text, sound or the like).

Meanwhile, if it is verified in step S712 that the inspection unit 110has a fault (i.e., it is verified that at least one of the light sources(i.e., the first light emitting element 221 b or the second lightemitting element 222 b) of the second lighting portion 220 is abnormal),the controller 140 generates a second verification result indicatingthat the inspection unit 110 is abnormal (S718), and outputs thegenerated second verification result through the output unit (S720). Thesecond verification result may be output in various forms (e.g., text,sound or the like).

FIG. 9 is a flowchart showing a process of providing a verificationresult in accordance with an embodiment of the present disclosure.Referring to FIG. 9, the controller 140 automatically verifies whetherthe inspection unit 110 has a fault in accordance with predeterminedinformation (e.g., the predetermined verification cycle) (S902), andgenerates the verification result (the first verification result or thesecond verification result) (S904). As one example, the firstverification result may include a verification result indicating “good”or “warning” of the inspection unit 110, and the second verificationresult may include a verification result indicating “bad” of theinspection unit 110. As another example, the first verification resultmay include a verification result indicating “good” of the inspectionunit 110, and the second verification result may include a verificationresult indicating “warning” or “bad” of the inspection unit 110.

The controller 140 stores the generated verification results in thestorage unit of the inspection system 100. In an embodiment, thecontroller 140 may sequentially store the verification results in thestorage unit of the inspection system 100 together with verificationdate/time information indicating the verification date/time of theinspection unit 110.

The controller 140 determines whether an instruction condition forgenerating a list of verification results (hereafter, referred to as“list generation instruction condition”) is satisfied (S908). Forexample, the list generation instruction condition may include inputinformation from a user or a predetermined time cycle. In an embodiment,the controller 140 determines whether input information for requesting alist of the verification results is received from a user through theuser input unit of the inspection system 100. In another embodiment, thecontroller 140 determines whether the predetermined time cycle isreached.

If it is determined in step S908 that the list generation instructioncondition is satisfied, the controller 140 searches the storage unit ofthe inspection system 100 (S910), generates a list of the verificationresults stored in the storage unit of the inspection system 100 (S912)and displays the generated list through the output unit of theinspection system 100 (S914). For example, the controller 140 maygenerate and display the list 1010 of verification results as shown inFIG. 10. In FIG. 10, reference numeral 1020 indicates an input windowfor selecting the number of verification results to be shown as a chartin the list 1010 of verification results, reference numeral 1030indicates a first input button for showing the verification resultscorresponding to the number inputted into the input window 1020 as achart, and reference numeral 1040 indicates a second input button forshowing at least one verification result selected by a user through theuser input unit as a chart.

The controller 140 determines whether input information for requestingdisplay of a chart of verification results (hereafter, referred to as“chart display request information”) is received from a user through theuser input unit of the inspection system 100 (S916). For example, thechart display request information includes information of selecting averification result and information of selecting (e.g., clicking) thefirst input button 1030 or the second input button 1040. If it isdetermined in step S916 that the chart display request information isreceived, the controller 140 generates the chart of verification resultsbased on the verification results corresponding to the chart displayrequest information (S918), and displays the generated chart through theoutput unit of the inspection system 100. For example, the controller140 may generate a chart 1110 of the verification results based on theverification results corresponding to the chart display requestinformation, as shown in FIG. 11. In FIG. 11, reference numeral 1120indicates a fault limit, that is, an error limit, reference numeral 1130indicates a warning limit, reference numeral 1140 indicates a referencevalue, and reference numeral 1150 indicates the verification results.Further, in FIG. 11, the horizontal axis of the chart 1110 is an indexof the list of the verification results and the vertical axis is averification result value of the verification results.

Although the present disclosure was described with reference topreferred embodiments, it would be understood by a person skilled in theart that the present disclosure may be changed and modified in variousways without departing from the spirit and scope of the appended claims.

1. A method of verifying whether an inspection unit, capable ofinspecting a defect of an inspected body, in an inspection system has afault, the method comprising: providing a verification reference bodyformed on a frame attached to the inspection system; positioning theinspection unit over the verification reference body; obtaining imagedata of the verification reference body through the inspection unit;verifying whether the inspection unit has a fault by extracting amovement error and a height error of the inspection unit from the imagedata; and generating a verification result indicating whether theinspection unit has a fault.
 2. The method of claim 1, wherein theverification reference body comprises a flat plate having a flat areacapable of indicating a height reference and a gray level, at least twofiducial markers disposed around the flat area, and a height markerdisposed around the flat area, and wherein verifying whether theinspection unit has a fault comprises: extracting a movement error ofthe inspection unit from image data of the at least two fiducial makers;and extracting a height error of the inspection unit from image data ofthe flat plate or the height marker. 3-6. (canceled)
 7. The method ofclaim 2, wherein extracting a movement error of the inspection unitcomprises: detecting the position of the at least two fiducial markersfrom the image data of the at least two fiducial markers; and verifyingwhether the inspection unit has a fault by comparing the detectedposition with a predetermined reference position of the at least twofiducial markers.
 8. The method of claim 2, wherein extracting a heighterror of the inspection unit comprises: detecting the height of theheight marker using the image data of the flat plate or the heightmarker; and verifying whether the inspection unit has a fault bycomparing the detected height with a predetermined height of the heightmarker.
 9. The method of claim 1, wherein positioning the inspectionunit over the verification reference body comprises positioning theinspection unit over the verification reference body based on aninspection defect rate of the inspection unit.
 10. The method of claim1, further comprising correcting a fault of the inspection unit bycalibrating the inspection unit based on the verification result.
 11. Aninspection apparatus for verifying whether an inspection unit, capableof inspecting a defect of an inspected body, in an inspection system hasa fault, the inspection apparatus comprising: a frame attachable to theinspection system; and a verification reference body formed on theframe, wherein the verification reference body comprises a flat platehaving a flat area capable of indicating a height reference and a graylevel, at least two fiducial markers disposed around the flat area, anda height marker disposed around the flat area.
 12. (canceled)
 13. Theinspection apparatus of claim 11, wherein the flat plate indicates aheight reference for verifying an accuracy of the height of theinspection unit.
 14. The inspection apparatus of claim 11, wherein theat least two fiducial markers indicate at least two positions forverifying an accuracy of movement of the inspection unit.
 15. Theinspection apparatus of claim 11, wherein the height marker indicates apredetermined height for verifying an accuracy of height measurement ofthe inspection unit.
 16. The inspection apparatus of claim 11, whereinthe verification reference body is disposed in a concave portion of theframe.
 17. The inspection apparatus of claim 16, further comprising: acover configured to be capable of opening and closing the verificationreference body disposed in the concave portion; and a driving unitmoving the cover with respect to the verification reference body to openand close the verification reference body.
 18. The inspection apparatusof claim 17, wherein the driving unit comprises a rotating unitconfigured to rotate the cover to open and close the verificationreference body.
 19. The inspection apparatus of claim 17, wherein thedriving unit comprises a sliding unit configured to slide the cover toopen and close the verification reference body.
 20. The inspectionapparatus of claim 11, further comprising a reflector disposed on theframe to verify whether a light source, configured to generate light, inthe inspection unit has a fault.
 21. The inspection apparatus of claim20, wherein the reflector has a convex curve shape.
 22. The inspectionapparatus of claim 20, wherein the reflector has a concave curve shape.23. An inspection system comprising: an inspection unit capable ofinspecting a defect of an inspected body; the inspection apparatus ofclaim 11; and a controller configured to position the inspection unitover the verification reference body, obtain image data of theverification reference body through the inspection unit, verify whetherthe inspection unit has a fault, and generate a verification resultindicating whether the inspection unit has a fault.
 24. The inspectionsystem of claim 23, wherein the controller is configured to position theinspection unit over the verification reference body based on aninspection defect rate of the inspected body by the inspection unit. 25.The inspection system of claim 23, wherein the controller is configuredto correct a fault of the inspection unit by calibrating the inspectionunit based on the verification result.